A wireless device may operate by communicating via radio waves using a system of base stations. The base stations may send and receive calls, and relay the calls to other base stations. The coverage of a base station may include the geographic area where the base station can communicate with the wireless device. In addition, a wireless device may operate using batteries as a power and/or energy source. The state of charge of the wireless device battery may include the amount of power and/or energy left in the battery compared with the amount power and/or energy the battery had when the battery was full.